Low-water alarm.



W. C. BLUNDELL.

LOW WATER ALARM.

APPLICATION FILED MAR. 2. 191

1,259,720, I Patented Mar. 19, 1918.

UNI'EE sanrow-warns ALAitM.

Specification of Letters Patent.

entertainers, 191's.

Application filed March 2, 1917. Serial No. 153,532.

To all whomitmoy concern: H v 7 Be it known that I, WILLIAM C. BLUNDELL,a citizen of the United States. residing at Los Angeles, in the countyof Los Angeles and State of California, have invented a new and usefulImprovement in Low-Water Alarms of which the following is aspecification.

My invention relates to low water alarms and signals for indicating thelow water stage in steam boilers and the like, and has for its objectthe provision of a device for this purpose which may be readily attachedto the different types of boilers and which embodies simplicity ofstructure and economy. v

A further object of this invention is to provide an alarm for indicatingthe low water stage in locomotive boilers particularly, but which may bealso used for stationary boilers.

A further object is to provide a device which includes an expansionelement connected with both the water and steam compartments of theboiler which may be heated by the steam and expanded for operating thesignal when the water in the boiler reaches the danger stage, and whichwill be readily cooled when the water supply has been replenished.

I am aware that the use of an expansion tube in a device of this kind isnot in itself new and that other devices for this purpose have beeninvented, patented and used .for a number of years but I am not awarethat any device has heretofore been used or known which embodies theimprovements set forth in this application. Other objects may appear inthe following description.

In the consideration of this invention reference is had to a formerinvention of mine relating to water indicating means for boilers asdisclosed in Letter Patent granted to me on April 10, 1917, PatentNumber 1.221.963; and also to another invention disclosed in anapplication for patent filed by me on Sept. 5, 1916, Serial No- 120,860.

. Referrirg to the drawings, Figure 1 is a front elevation of my alarmdevice showing a form for use in connection with locomotive boilers.Fig. 2 is a plan of the same, Fig. 3 is a right hand end elevation ofthe same, and Fig. 4 is a left hand elevation of Fig; 1 showing amodified form of device.

Similar characters of reference are used in the -specification andin-theseveral views of the drawings for indicating similar and like parts.

In the form of device shown in Figs. 1, 2, and '31 provide a watercolumn 1 which has extensions 2 and 3 formed thereon near the top andbottom, respectively. lhe interior of the water column 1 is subdividedinto two compartments, the upper compartment 4 being the. shorter of thetwo and being separated from the lower compartment 5 by means of thepartition 6. The upper compartment 4 is connected with the steamcompartment of the boiler 7 by means of a pipe 8 and an elbow 9, and avalve 10 is connected with the pipe 8 intermediate of the water column 1and the boiler 7 so that the steam supply from the boiler may beregulated or shut off" as desired.

The lower compartment 5 of the water column is connected with the watercompartment of the boiler 7 by means of a pipe 11, an elbow l2 and thepipe 13, a dripcock 14 being connected with the pipe 11 and the elbow 12for draining the water therefrom, and a valve 15 being connected withthe elbow 12 and the pipe 13 for regulating or shutting off the waterfrom the water column. The extension 3 occupies a position on the watercolumn 1 which is slightly above the low water stage in the boiler and apassage 16 is formed therein which communicates with the water chamber 5of the water column.

One end of an expansion tube 17 is threaded or otherwise suitablysecured in the passage 16 of the extension 3 so that the interior of thetube will communicatewith the chamber 5 in the water column. The outerend of the tube 17 is attached to a T 18 which is closed at the outerend by means of a plug 19. p p

The extension 2. of the water column has a passage 20 which communicates,with the steam chamber 4 and is connected with a pipe 21 whichterminates at its outer end in a T 22. A whistle 23 is attached by meansof the base 24 and a pipe 25 to the T 22, and a flexible tube 26connects the T 18 on the expansion tube 17 with the T 220m the pipe 21.Suitable unions 27 are provided on the ends of the flexible tube 26 forfacilitating the attachment of the tube to the Ts. Thus, anuninterrupted passage for the Water and steam is provided for connectingthe chamber 4, the tube 26, the tube 17, and the chamber 5 and the tube25 in which the water from the boiler may rise to a height to correspondto that in the boiler, and when the low stage of water is reached thesteam may descend through the chamber 4 and the tube 26 into theexpansion tube 1.7, and thus displace the water for expending the tube17.

The plug 19 on the end of the T 18 is slottedto' receive and serves topivotally' hold a vertically disposed lever 28. The lower end of thislever is pivotally attached to a horizontally disposed rod 29 which isrigidly attached at the other end by means of nuts 31 to a depending lug30 formed on the outer end of the extension 3. The upper end of'thelever 28 is pivotally attached to the outer end of a rod 32 and theother end of this rod is similarly attached to the lower end of thewhistle lever 33 which operates the valve stem 31 of the whistle, in theusual manner.

The leverage of the lever 28 is such that a very slight movement of thelower end, caused by the expansion of the tube 17, will effect asuflicient movement of the upperend of the lever to operate the whistle23. It will be observed that when this device is attached to the boilerin the manner shown, in the event that the water in the boiler is abovethe level of the pipe 8 the chambers 4: and 5 in the water column, thetubes 17 and 26 and the pipes 21 and 25 will be filled with water and itwill be impossible for the steam to gain access to the whistle valve 24but when the water descends below the level of the pipe 21, the steamwill enter this pipe and be admitted to the pipe 25 into contact withthe whistle valve. In such case the tube 17 and a portion of the tube 26will be filled withwater as the stage of the water in the b01161 in suchevent, will be above the low water stage. lVhen, however, the low waterstage is reached the steam will enter the tube 17 through the tube 28and the T 18, thus replacing the water, and heating the tube 17 andcausing it to expand. It is obvious that the expansion of the tube 17will move the plug 19 and the T 18 outwardly from the water column butthe lower end of the lever 28, in. such case, is held against movementby the rod 29 which is stationary, and the upper end of the lever 28 ismoved outwardly and serves to operate the whistle valve stem 3% by meansof the lever 33, thus admittingthe steam to the whistle and sounding analarm.

By reference to Fig. 1 it will be observed that the water column 1 maybe dispensed with in some cases and steam pipes 8 and 13 which areconnected with the boiler may be attached directly to the pipe 21 andthe tube 17. In such case a lug 30 which is similar to the lug on theextension 3 may be provided on the elbow 35 attached to the pipe 13 inorder to provide means for attaching the rod 29 thereto.

A valuable feature of this invention consists in the connection of'thetube 17 with both the water and steam compartments of the boiler.Experience has proven that should this expansion tube be connected onlywith the steam compartment, while it will heat rapidly when the steam isad mitted into it, it will not cool rapidly enough and the alarm willcontinue to sound for some time after the water. has been replenished.In my improved device however as soon as the water in the boiler risesso that it may enter the tube17, this tube will be cooled immediately toa temperature suflicient to contract the tube and shut otl the steamsupply from the whistle.

It should be understood that 1 do notlimit myself to the use of awhistle or to an alarm, as it obviously is possible to provide amechanical signal which may be operated by the steam pressure; nor do Ilimit myself to the exact form of the other elements shown, for it isconceived to be possible to.

modify the structure somewhat to meet different conditions obtainingwith different types of boilers.

Having thus described my invention what I claim is:

1. A low water alarm for steam boilers including an expansible tubeconnected at opposite extremities with the steam and water portions ofthe boiler and positioned wholly between the high and low water levelsof the boiler to permit the circulation of steam and water therethrough,and signaling means connected with and arranged for operation by theexpansion of said tube.

2. A low water alarm for steam boilers comprising an expansible tubeconnected with the steam and water compartments of the boiler andpositioned between the high and low water levels thereof, signal meansattached to and arranged for operation by the expansion of said tube,and operating means for said signal.

3. A low water alarm for steam boilers comprising a water and a steamconnection with th boiler at the low and high water levels,respectively, a signal attached to said steam connection, an expansibletube connected with said water connection and with said signalandarranged'to permit the circomprising a horizontally extended steam Vconnected with said steam connection, and a flexible connection foraffording communication between said tube and said signal.

5. A low water alarm for steam boilers comprising separate water andsteam con nections from the boiler at the low and high water levels,respectively, an expansion tube for affording communication therebetweenand arranged for being completely filled with water and steam accordingto the stage of the Water in the boiler, and steam actu ated signalingmeans connected with said steam connection and with said tube foroperation coincidently with and by the expansion and contraction ofsaid-tube.

6. A low water alarm for steam boilers comprising steam and waterconnections extending from the high and low water levels of the boiler,a water and steam column connected with and supported therebetween andhaving disconnected steam and water compartments, an expansion tube incommunication with the water compartment therein, a steam pipecommunicating with the steam compartment therein, a connection betweenthe outer extremity of said tube and said steam connection, a signal incommunication with said steam connection, and signal actuating meansoperable by the expansion and contraction of said tube.

7. A low water alarm for steam boilers comprising separate steam andwater chambers connected, respectively, with the steam and watercompartments of the boiler, an expansion tuloe communicating with saidwater compartment and supported substantially in the plane of the lowwater level, a steam connection leading from said steam chamber andcommunicating with the outer extremity of said tube, a steam actuatedsignal connected with said steam connection intermediate of said steamchamber and said tube, and signal operating means supported on andoperable by the expansion of said tube.

8. A low water alarm for steam boilers comprising a rigid support havingseparate water and steam chambers therein connected, respectively, withthe water and steam portions of the boiler, an expansion tube supportedthereon and disposed in the plane of the low water level, a steamconnection between said tube and said steam chamber, a signalcommunicating with said steam connection and positioned intermediate ofsaid tube and said steam chamber, an operating member rigidly held atone end on said support, attached to said tube and also attached to saidsignal, for admitting steam to the signal coincidently with theexpansion of said tube.

9. A low water alarm for steam boilers comprising a horizontallydisposed expan sion tube supported substantially in the plane of the lowwater level of the boiler and communicating at opposite extremities withthe steam and water portions of the boiler, a signal communicating withthe steam compartment thereof, and operating means for admitting steamto the signal coincidently with the expansion of said tube.

10. A low water alarm for steam boilers comprising a continuousconnection mount- Copies of this patent may be obtained for five centseach. by addressing the Commissioner of Patents,

Washington, D. C.

